Diazotype photographic copying material for heat development

ABSTRACT

A DIAZOTYPE PHOTOGRAPHIC COPYING MATERIAL THAT IS HEAT DEVELOPABLE IS COMPRISED OF A SUPPORT HAVING FORMED THEREON A LIGHT-SENSITIVE LAYER CONSISTING ESSENTIALLY OF A LIGHT-SENSITIVE DIAZONIUM COMPOUND AND AN AZO DYE COUPLER CONSISTING OF A POLYHYDROXYBENZOIC ACID COMPOUND.

United States PatentO 3,740,229 DIAZOTYPE PHOTOGRAPHIC COPYING MATE- RIAL FOR HEAT DEVELOPMENT Shoji Maruyama, Sagamihara, Etsuo Oida and Takao Hamada, Tokyo, Tomiaki Asami, Yokohama, and Susumu Iwata, Tokyo, Japan, assignors to Kabushiki Kaisha Ricoh, Tokyo, Japan No Drawing. Continuation-impart of abandoned application Ser. No. 709,190, Feb. 29, 1968. This application Apr. 12, 1971, Ser. No. 133,442

Claims priority, application Japan, Mar. 7, 1967, 42/ 14,295 Int. Cl. G03c N58 US. Cl. 96--91 R 15 Claims ABSTRACT OF THE DISCLOSURE A diazotype photographic copying material that is heat developable is comprised of a support having formed thereon a light-sensitive layer consisting essentially of a light-sensitive diazonium compound and an azo dye coupler consisting of a polyhydroxybenzoic acid compound.

CROSS REFERENCE TO RELATED APPLICATION This is a continuation-in-part of application Ser. No. 709,190, filed Feb. 29, 1968, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a heat developable diazotype copying material.

Description of the prior art The known diazotype photographic copying materials which are heat developable have the advantages of ease of handling during the reproduction process, yet they possess a number of inherent disadvantages. The lightsensitive layers of the conventional heat developable diazotype copying materials necessarily contain all the components of reaction that participate in the development of color. This is a major disadvantage and commonly leads to premature reaction during storage, causing the known phenomenon of fogging. Moreover, these components of reaction are necessarily heat responsive, and are hence prone to deterioration at elevated storage temperatures.

The heat developable copying materials that have been in use up to this time are consistently designed to function by producing colored images through the action of a base, released during heat development, and contain in the light-sensitive layer a base-generating agent such as urea or an alkali metal salt of an organic acid to effect the azo coupling in an alkaline environment, said environment being generated during the process of heat development. This inclusion of urea or similar base generating substance in the light-sensitive layer which also contains the diazo compound as well as the coupler, potentiates the precoupling reaction and it often occurs prematurely to cause fogging in the materials before use. Moreover, the loss of urea tnd similar substance from the light-sensitive layer to the support is likely to occur during storage, causing deterioration in image-forming qualities after storage, usually manifested by reduced color density of the copied image. Attempts to compensate for this loss by using excessive amounts of urea or the like in the light-sensitive layer have led to extremely undesirable soiling or fouling of the copying equipment, especially during continuous operation.

Attempts to control the pre-coupling phenomenon have been made, such as including a fourth ingredient in the light-sensitive layer, calculated to prevent reactive contact between the diazo compound, the coupler and the commonly used color development accelerator. These attempts have been notably unsuccessful, all resulting in fogged materials, particularly when stored at conditions of elevated temperatures and humidity. Furthermore, the presence of such ingredient interferes with the normal heat development of a clear copy during use.

Thus, the prior art has provided the following technology. U.S. Pat. Nos. 3,169,067 :and 3,224,878 are concerned with the use of urea, alkylurea and the like as alkali-generating agents, but the copying materials described therein possess the serious fog phenomenon, caused by the chemical reaction of the components, owing to their co-existence in the same support layer potentiated during storage of the copying materials. British Pat. 815,005 and French Pat. No. 1,255,950 suggest diazotype photographic copying materials whose intermediate layers are composed of Waxy materials, but such copying materials suffer from a decline of coupling ability. The drawbacks incidental to aforesaid diazotype photographic copying materials are caused principally by the use of an alkali generating agent in the light-sensitive layer. .For this reason, blending a halogenated salt of acetic acid high in thermodecomposition efliciency into the light-sensitive layer has been suggested in U.S. Pat. Nos. 2,653,091 and 3,166,422, such as sodium, potassium, ammonium or mono-, dior tri-ethanol amine salt of trichloroacetic acid. However, such diazotype photographic copying materials lack acceptable shelf life. In British Pat. No. 983,665, it has been proposed to use a pyran or a thiopyran derivative as a coupler for diazotype photographic copying materials. However, this copying material is inferior in shelf life owing to a high coupling activity of the coupler, and the very serious drawback of causing a yellow coloration of the non-image area after reproduction due to the coupler itself taking on a yellow color. US. Pat. No. 3,331,689, British Pat. No. 1,078,912, Dutch Pat. No. 6,407,760 and Japanese publication No. 19,228/ 1968 suggest the use of resorcylic acid or phloroglucinol carboxylic acid and their derivatives as couplers for diazotype photographic copying materials to provide copying materials of a highly improved shelf. life, but such compounds produce undesirable coloration or change in coloration in the copies. Comparative data in this respect is provided below.

SUMMARY OF THE INVENTION This invention provides a diazotype photographic copying material, an article of manufacture that is heat developable having improved shelf life and stability of copied image by means of the inclusion in the lightsensitive layer of said material a novel coupler component, a hydroxybenzoic acid compound of the formula HO OH in which R R and R are selected from the substituents selected from the groups tabulated below and used in the combinations of R R and R as tabulated below.

1 H, Cl, Br, I and Lower alkyl and II, Cl, Br and I,

lower alkyl lower alkoxy wherein at least radicals having radicals having one of R1 and Rs 1-6 carbon atoms. 1-6 carbon atoms. is Cl, Br or I.

2 Lower alkyl, lower H II, Cl, Br and I.

alkylamincs, [(6- hydi'oxyethyl) amino] methyl radical and morpholino lower alkyl radicals, wherein the alkyl has 1-6 carbon atoms.

There follows a typical example of the preparation of the polyhydroxy benzoic acid compounds which characterize the novel articles of this invention.

PREPARATION (1) Synthesis of B-ethyl-S-bromo-y-resorcylic acid which is expressed by the chemical formula:

First, 4-acetylresorcin is prepared, according to Hoesch' 15 synthesis method, from resorcin as the starting material.

This 4-acetylresorcin is subjected to Clemensen reduction to synthesize 4-ethylresorcin. Then, a mixture consisting of 1.0 part by weight of this 4-ethylresorcin, 1.5 parts by weight of potassium bicarbonate and 1.0 part by Weight of 20 Water is subjected to reaction therebetween in a carbon dioxide gas atmosphere and at a temperature ranging from 120 C. to 130 C. for 3 hours in an autoclave. The resulting product is then dissolved in water. The insolu- Compound 1 2 Ra 3-chloro-4methylw-resorcylic acid C1 CHa -H 3,5-dichl0r0-4rmcthyl'y-resorcy].ic acid. --C1 CH; -01 3-bromo-4-methyl-yresorcylic acid- B r C H H 3,5-dibromo-4-methyl-'y-resorcylic acid. Br CE Is Br 3-bromo-4-metl1oxy-v-resorcylic acid r 0 CH H 3,5-dibromod-methoxy-y-resorcylic acid- Br OCH; Br 3,5-dichloroiqnethoxywresorcylic acid --0 CH; 01 3-brorn0-4-methoxy-5-chloro-y-rcsorcylie Br 0 CH -01 3,5-dii0do-4-ethoxy-y-resorcylie acid I O CzH5 -I 3,5-diiodo-4metlioxy-y-resorcylic acid I -0 CH -1 3-hromo-4-ethoxy-y-resorcylic acid r -0 C 2H -11 3,5-dichloro-4ethyl--y-resorcylic aci Cl CzH Cl 3,5-di bromo-4propyl"y-resorcylic a Br C H Br 3-(morpholino) methyl-'y-resorcylic acid C HzN H 0 -H -H 3-(mcthyl) amino-y-rcsorcylic acid CH3) -H H 3- (methyl) amino-5-brorno-v-resorcylic acid a) H Br 3-methyl-fi-bromo-- -resorcyl.ic acid CH3 H Br 3-hexyl 5-chlo o-'y-resorcylie acid s ia H Cl 3-methyl-5chloro-'yresorcylic acid. CHa H Cl 3-ethyl-5-iodo-v-resorcylic acid. z s H I 3-ethyl-fi-chloro-y-resorcylic acid. -C2H5 --H -Cl 3-l(B-hydroxyethyl)amino]rnethy 'y CH2 HCH2 2OH H --B 3(isopropyl)amino-5cl1lor0-y-resorcylic acid. NHCH(CH3)2 H -01 S-(morpholino) mcthyl-5-iodo-w-resorcylic acid CHr-N H 0 H I 5'chl0ro4-m ethyl-'y-resorcylic acid --H CH Cl fi-bromoA-methyl-y-resorcylic acid. -H --CH; --Br 5-bromo-4-methoxy-v-resorcylic acid. H 0 CH3 B r 5-i0do-4ethoXy-'y-resorcylic acid. H O C2H I 5-chloro4-propyl-y-resorcylic acid. -H CaH7 -Cl 3,4-dimethyl-y-resorcylic acid CH3 CH -H 3,4-dipropyl-fi-chloroywesorcylic acid. -CaH7 -C3H -C1 3-ethyl-4hexyl-5-bromo-y-resorcylic acid. z s CoHm Br 3-methyl-4-meth0Xy-7-resorcylic acid CHa OCHS H 3-ethyl4-ethoXy-5-chloro-w-resorcylic acid CzHs O CZHfi Cl 3-hexyl-4-butoxy5-i0do-- -resoroylic acid 001113 0 0 1-1 I The above polyhydroxy benzoic acid compounds can be prepared by known methods. In a typical preparation, a resorcin or a phloroglucin compound is heated, together with an alkali metal carbonate, in water or in an inert solvent such as dimethylformamide, in a gaseous carbon dioxide atmosphere to introduce the carboxyl radical. The compound can then be halogenated with a halogenating agent such as idoine chloride, bromide or sulfuryl chloride in a solvent such as diethyl ether or glacial acetic acid.

The color portion of the copied image using an iron chloride agent, of any one of the novel couplers described above is invariably blue. The couplers of this invention are insoluble or difficultly soluble in water, but it can be rendered water-soluble by using as a solubilizing agent an alkali metal carbonate, e.g. sodium or potassium citrate or acetate, or guanidine carbonate. These agents can therefore be used to facilitate the preparation of the solutions for use in the formation of light-sensitive layers acs rd s to h s invention.

ble substances, if any, are filtered out. The filtrate is then added with a diluted sulfuric acid. As a result, there occurs precipitation of 3-ethyl-'y-resorcylic acid. In this way, 0.61 part by weight of coarse intermediate product having a melting point in the range of from 124 C. to 128 C. is obtained. By effecting the recrystallization of this intermediate product in a water-containing methanol, there are obtained crystals which are practically odorless and which are of a melting point (dec.) of 147 C. Then, 1.0 part by weight of this coarse intermediate product consisting of said 'y-resorcylic acid derivative is dissolved in 18 parts by weight of glacial acetic acid at room temperature. While introducing, in drops, a total of 1.1 parts by weight of bromine into the resulting solution, the mixed solution is stirred for 2 hours to cause a reaction. Thereafter, the glacial acetic acid is concentrated under a reduced pressure. As a result, the desired product which is light yellow in color is precipitated. By effecting the recrystallization of the aforesaid latter product in a dishlqrcetha s solut o hat i obtai ed 0. 2 p t by Weight of colorless crystals having an M.P. (dec.) of 148 C.

(2) Synthesis of 3,S-dichloro-4-methoxy-v-resorcylic acid which is expressed by the chemical formula:

ooon 5 HO OH I OCH;

1.0 part by weight of phloroglucin is dissolved in an aqueous solution of percent caustic soda. While gradually introducing, in drops, a total of 1.3 parts by weight of dimethyl sulfuric acid into the resulting solu tion at 40 C., the resulting mixed solution is allowed to react for 2 hours. Then, the resultant reaction product (oily matter) is subjected to fractional distillation under a reduced pressure, with a result that phloroglucin monomethylether having a boiling point ranging from 180 C. to 185 C. at a pressure ranging from 7 to 8 mm. Hg is distilled outwith a yield of 0.48 part by weight.

Then 1.0 part by weight of this phloroglucin monomethylether, 2.0 parts by weight of potassium bicarbonate and 5 parts by Weight of water are placed in an egg-plant type flask. While passing carbon dioxide gas thereto, the mixture is boiled for 1.5 hours. After the resulting mixture has been cooled, the latter is acidified by the use of a diluted sulfuric acid. As a result, 0.87 part by weight of 4-methoxy-v-resorcylic acid is obtained. This coarse intermediate product is of an M.P. (dec.) of 136 C. The purified product which is prepared by subjecting this coarse intermediate product to recrystallization in a watercontaining methanol or glacial acetic acid exhibits an M.P. (dec.) of 143C. i

1.0 part by weight of the 'y-I'BSOICYllC acid derivative thus obtained is then dissolved in 8 parts by weight of ether. While introducing, in drops, a total of 2.4 parts by weight of sulfuryl chloride into this solution at room 40 temperature, the resulting mixed solution is allowed to react for 2.5 hours. Thereafter, the reacted solution 18 heated for 30 minutes in a hot water bath which is held at C. As a result, there deposit crystals. The crystals thus deposited are then filtered out and washed with water thoroughly. In this way, the desired product crystals having an M.P. (dec.) of 216 C. are obtained with a yield of 0.82 part by weight. By effecting the recrystallization of these crystals in glacial acetic acid, they turn into needle-form colorless crystals having an M.P. (dec.) of 220 C.

According to the'present invention, the polyhydroxy benzoic acid derivative obtained, for example, in the foregoing manner can be admixedas the coupler component-in the light-sensitive layer of a diazotype photographic copying material intended for heat development to thereby eliminate the various drawbacks of the copying materials of this type of the prior art. The components other than said coupler component of the light-sensitive layer can be any of those materials that have been used in the formation of the light-sensitive layers of the copying materials of the prior art.

For example, typical diazo compounds which are suitable for use with the coupler component of this invention are:

(a) 4-diazo-N-methyl-N-benzylaniline (b) 4-diazo-N-ethy1-N-benzylaniline (c) 4-diazo-N-hydroxyethyl-N-benzylaniline (d) 4-diazo-N-cyclohexyl-N-benZylaniline (e) 4-diazo-N-propyl-N-ethylaniline (f) 4-diazo-N-propyl-N-hydroxyethylaniline (g) 4-diazo-N-dipropylaniline (h) 4-diazo-l-morpholinobenzene (i) 4-diazo-2,S-diethoxy-l-morpholinobenzene (j) 4diazo-N-phenylaniline 6 (k) 4-diazo-N-dimethylaniline (l) 4-diazo-N-diethylaniline (m) 4-diazo-N-ethyl-N-hydroxyethylani1ine (n) 4-diazo-3-chloro-N-dimethylaniline and (o) 4-diazo-2,5-diethoxy-l-tolylthiobenzene.

When one of the diazo compounds enumerated in the items (a) through (g) is made to react with one of the aforesaid coupler components, there is produced an azo dye which is blue in color. When the diazo compounds enumerated in the items (h) through (j) are made to react with one of said coupler components, there are pro duced azo dyes which are reddish violet, violet and bluish violet in color, respectively. When one of the diazo compounds enumerated in the items (k) through (0) excluding (11) is made to react with one of said coupler components, there is produced an azo dye which is blue in color. When the diazo compound mentioned in the item (11) is made to react with one of said coupler components, there is produced an azo dye which is reddish brown in color. Also, these diazo compounds can be used, in general, in the form of a double salt of such diazo compound and a metal chloride such as zinc chloride and cadmium chloride.

For the purpose of accelerating the color development which is caused by the coupling reaction between. these diazo compounds and said coupler components and also for the purpose of improving the: clarity and the color density of the formed azo dyes at the time of the heat development, the present invention includes the optional use of a color development accelerator in the components which constitute the light-sensitive layers of the copying materials. Such a color development accelerator which is particularly suitable for these purposes includes urea, its derivatives-such as methylureaand also includes thiourea and its derivatives. Also, organic acid amides such as benzamide, crotonamide and malonamide, and polyhydroxy compounds, such as sorbitol, mannitol and pentaerythritol, are also suitable. Known base-generating agents which produce alkaline compounds by the application of heat can be used. It is well known to use various assistants as mentioned above for diazotype copying material, as described, for instance, in US. Pat. Nos. 3,169,067, 3,224,878, 3,255,007, 3,386,828, 3,453,112, 3,480,437 and 3,166,422. However, the remarkable properties of the articles of this invention obtained. through the co-usage of such assistants with the specific coupling components as employed in the present invention are not suggested.

Moreover, as a component of the light-sensitive layer and being capable of further suppressing the occurrence of the pre-coupling phenomenon and being accordingly capable of preventing the so-called fog phenomenon from taking place during the storage of the copying material of the present invention, the employment of metal salts of organic as well as inorganic acidssuch as zinc acetate, aluminum chloride, cadmium sulfate, cadmium nitrate and cadmium chlorideis suitable also.

Furthermore, the addition of a xanthine compoundsuch as cafieine, theophilline and theobromine to the solution with which a light-sensitive layer is formed is effective in arresting the production of preciptates arising from possible reaction between the diazo compound and the coupler component, or in other words, such an addition of a xanthine compound is effective in suppressing such an undesirable reaction.

According to the present invention, a solution for forming a light-sensitive layer is prepared by dissolving or dispersing, in water, the respective light-sensitive layer components which have been already described, and by applying this solution onto one face of a support and thereafter drying the same, whereby there is obtained a desired diazotype photographic copying material adapted for heat development. In preparing the solution, the desirable proportion of the coupler component consisting of polyhydroxy benzoic acid compound to the diazo compound is such that the amount of the coupler component is in the range of from 1.0 to 10.0 parts by weight to 1.0 part by weight of the diazo compound.

It is desirable that the color development accelerator which is another material for forming the light-sensitive layer is mixed in an amount in the range of from 0.1 to 10.0 parts by weight to 1.0 parts by weight of the diazo compound.

Further, the desired amount of the aforesaid metal salt which is mixed and which is capable of preventing said fog phenomenon ranges from 0.1 to 3.0 parts by weight to 1.0 part by weight of the diazo compound.

Still further, the desired amount of the aforesaid xanthine compound which is admixed at the time of preparing the solution for forming a light-sensitive layer is in the range of from 0.5 to 10.0 parts by weight to 1.0 part by weight of said diazo compound contained in said lightsensitive layer.

The color development accelerator, metal salt and xanthine compound as described above are all assistant components or optional ingredients for constituting the light-sensitive layers of the copying materials, and it is preferable in the case of the present invention to use one or two and more of these components together with the diazo compound and the coupler component.

A light-sensitive layer having a composition consisting of the aforesaid proportions will achieve effectively the objects of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 Onto a support having a precoated layer containing silica and starch was applied a light-sensitive solution of the following composition and the resultant support was dried to obtain a diazotype photographic copying material.

Light-sensitive solution:

3,5 dichloro 4 methyl-' -resorcylic acid gr 2.0 Sodium citrate gr 1.0 Caffeine gr 5.0 4 diazo N phenylaniline zinc chloride double salt gr 0.8 Citric acid gr 2.3 Thiourea gr 0.5 Dicyandiamide gr 2.0 Saponin gr 0.1 Water ml 10 The said solution was applied onto a support and same was dried to obtain a diazotype photographic copying material adapted for heat development. The thus obtained copying material was placed on an original carrying a desired image, and the assembly was exposed to ultraviolet radiation. Thereafter, the exposed copying material was subjected to heat development at 170 C. for seconds. The developed image was noted to be the same image as the original one and was blue in color.

Example 2 Onto a support similar to that used in Example 1 was applied a light-sensitive solution according to Example 1 wherein the coupler and diazo compound were replaced with 3-bromo-4-methoxy-v-resorcylic acid (2.0 gr.) and 4-diazo-N-propyl-N-ethylaniline zinc chloride double salt (0.8 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The assistants other than above compounds were the same as those used in Example 1. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue in color.

Example 3 A solution for forming a light-sensitive layer and having the followi g compo tion;

3 bromo 4 methyl-'y-resorcylic acid gr 1.5 Sodium citrate gr 1.0 4-diazo-N-ethyl-N-benzylaniline zinc chloride double salt gr 1.0 Urea gr 5.0 Aluminum chloride gr 0.5 Caffeine gr 2.0 Water cc was applied onto a support and was dried to form a lightsensitive layer thereon. Thus, a diazotype photographic copying material for heat development was obtained. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue in color. In general, those copied images which are obtained by the use of copying materials where a polyhydroxy benzoic acid is used as the coupler component will undergo a change in color when contacted by ammonia, with the color of the images turning into yellow. However, no such change in color occurred with the copying material obtained in this example. Also, this copying material had a superior shelf-life.

Example 4 Onto a support similar to that used in Example 1 was applied a light-sensitive solution according to Example 1 wherein the coupler and diazo compound were replaced with 3-ethyl-5-bromo-'y-resorcyclic acid (2.0 gr.) and 4- diazo-N,N-dipropyl aniline zinc chloride double salt (0.8 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The assistants other than above compounds were the same as those used in Example 1. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue in color.

Example 5 Onto a support similar to that used in Example 1 was applied a light-sensitive solution according to Example 4 wherein only the coupler was replaced with 3,5-dibromo- 4-methoxy-y-resorcylic acid (2.0 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The assistants and diazonium compound other than above compound were the same as those used in Example 4. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue in color.

Example 6 Onto a support similar to that used in Example 1 was applied a light-sensitive solution according to Example 1 wherein the coupler and diazo compound were replaced wtih 3,S-diiodo-4-ethoxy- -resorcylic acid (2.0 gr.) and 4-diazo-2,5-diethoxy-1-morpholinobenzene zinc chloride double salt (0.8 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The assistants other than above compounds were the same as those used in Example 1. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue in color.

Example 7 Onto a support similar to that used in Example 1 was applied a light-sensitive solution according to Example 1 wherein only the coupler was replaced with B-(methyl) amino-'y-resorcylio acid (2.0 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The assistants and diazonium compound other than above compound are the same as those used in Example 1. The said copying material was subjected to the same procedure as that of Example 1. The developed image was noted to be blue violet in color.

Example 8 Onto a support similar to that used in Example 1 was applied a, light-sensitive solution according to Example 1 9 wherein the coupler and diazo compound were replaced with 3-(methyl)amino-S-bromo-y-resorcylic acid (2.0 gr.) and 4-diazo-N-cyclohexyl-N-benzylaniline zinc chloride double salt (0.8 gr.), and the resultant support was dried to obtain a diazotype photographic copying material. The

by a molal equivalent of 3,5-dibromo-2,4,G-trihydroxy benzoic acid, and thereafter the operation was carried out in the same manner as described under paragraph (a) to obtain the copying material.

d Pre aration of rio art co tro co 'n material assistants other than above compounds were the same as 5 p p r n l pyl g Control 3 those used in Example 1. The said copying material was 0 subjected to the same procedure as that of Example 1. T he ere was prepared a solutlon having a composition developed image was noted to be blue violet in color. g l l tobthat descflbedlln ParagFaPh above, 1 1

t at t e 3- rorno-4-methy -'y-resorcylic acid was rep ace COMPARATIVE DATA m by a molal equivalent of 3,5-dibromo-4-benzoyloxy-'y- A series of tests were carried out in the following way. resorcylic acid, and thereafter the operation was carried Preparation of copying materials: out in the same manner as described under paragraph (a) (a) Preparation of a copying material according to to obtam the copymg material Example 3 (e) Preparation of prior art control copying material A solution for forming a light-sensitive layer and having Control 4 the following composition: There was prepared a solution having a composition identical to that described in paragraph (a) above, except g gf g g ig methyl'ylresorcyhc and that the 3-bromo-4-methyl-'y-resorc-ylic acid was replaced 1r by a molal equivalent of 3-methyl-5-bromo-2,4,6-trihy- 4 'dlaZO N ethyl-N-benzylan1l1ne zinc chloride dioxy benzoic ac1d, and thereafter the operation was double salt gr 1.0 d t d d d Urea gr i0 cam;l 011 m b e 521111116 manner as esclri e un er para- 0 Aluminum chloride 05 r ail e copymg matena Caffeine gr 2.0 est met I Weter 100 g denslty was applied onto a support and was dried to form a light- Each of said copying materials was divided into two sensitive layer thereon. Thus, a diazotype photographic parts. One part of each copying material was immediately copying material suit bl fo heat development a bsub ected to reproductlon, and the other was subjected to rai ed, reproduction after fived days coercive aging in an atmos- As above, copying materials were made in accordance phere of 50 C. and 20 percent RH. Then, the densities of with Exam l 1, 2, 4, 5, 6, 7 and 3, the images formed on the surface of each of said copy- P e rafo of art cont 01 co in ing materials and the non-image area thereof were rer Pa 1 n pn Com 1 py g 1 spectively measured by means of Macbeth densitometer m manufactured by Macbeth Co. The reproduction was car- There was prepared a solution having a composition ried out by heat development, by using a copying machine identical to that described in paragraph (a) above, except of Ricopy Dry II type manufactured by Kabushiki that the 3-bromo-4-methyl-'y-resorcylic acid was replaced Kaisha Ricoh. by a molar equivalent of 3,5-dibromo- -resorcylic acid, (b) Color shift and thereafter the operation was carried out in the same manner as described under paragraph (a) to obtain the Py g mammals Were sublected t0 reproductlon copying i p immedlately after the preparation thereof and the thereby P f t t l t formed imaged copy was left to stand in a normal atmos- (c) repara Ion 0 Pnor ar con m copying ma ena phere for 10 consecutive days and the color shift was Control 2 observed. There was prepared a solution having a composition Results: identical to that described in paragraph (a) above, except The results of the above tests are shown in the followthat the 3-bromo-4-methyl-y-resorcylic acid was replaced ing Table 1.

TABLE 1 Shelf life according to test Color shift according method (a) to test method (b) Image Image density density- Time to image non image form precip- Days area area Days Image color itate, hrs. Examplole. --i g 8:3 1;; -gfftaifii: 96 Example 3 S3 3: 1 3 10 jidf. 96

0 s it? as si 0 Example;

5 1.13 0.10 10 B132 violet. Examples --i 5 ti? $193 96 2 a? 3:28 96 2 tit as .2 ases 72 Examples 2 t8? 8:93 18 it 72 t 2 as 8:93 12 7 Control 2 g g? 31 g3 96 Control 3 g 1 g? (8,: 2g 48 a 0:90 0115 10 Brown 48 *This value is the time required for a sample of the initial solution, placed in a. brown bottle and let stand at 20 C. to begin to show a perceptible amount of precipitate.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A diazotype photographic copying material for heat development, which comprises a support having formed thereon a light-sensitive layer comprising a light-sensitive diazonium compound and an azo coupling component selected from the group consisting of compounds having the formula HO OH in which R is selected from the group consisting of H, Cl, Br, I and alkyl having from 1 to 6 carbon atoms; R; is selected from the group consisting of alkyl and alkoxy having from 1 to 6 carbon atoms; and R is selected from the group consisting of H, Cl, Br and I; and wherein at least one of R and R is Cl, Br and I.

2. A diazotype photographic copying material for heat development, which comprises a support having formed thereon a light-sensitive layer comprising a light-sensitive diazonium compound and an azo coupling component selected from the group consisting of compounds having the formula (IJOOH HO OH Ra Rx in which R is alkyl having from 1 to 6 carbon atoms; R is H; and R is selected from the group consisting of H, Cl, Br and I.

3. A diazotype photographic copying material for heat development, which comprises a support having formed thereon a light-sensitive layer comprising a light-sensitive diazonium compound and an azo coupling component selected from the group consisting of compounds having the formula in which R is selected from the group consisting of alkylamino wherein the alkyl has from 1 to 6 carbon atoms (B-hydroxyethyl), amino methyl and morpholinoalkyl wherein the alkyl has from 1 to 6 carbon atoms; R is H; and R is selected from the group consisting of H, Cl, Br and I.

4. A diazotype photographic copying material according to claim 1, in which the light-sensitive layer further contains at least one assistant component selected from the group consisting of a color development accelerator, a metal salt and a Xanthine compound, said color development accelerator being selected from the group consisting of urea, methylurea, thiourea, benzamide, crotonamide, malonamide, sorbitol, mannitol and pentaerythritol, said metal salt being selected from the group consisting of zinc acetate, aluminum chloride, cadmium sulfate, cadmium nitrate and cadmium chloride and said xanthine compound being selected from the group consisting of caffeine, theophilline and theobromine.

5. A diazotype photographic copying material according to claim 1, wherein said light-sensitive diazonium compound is one member selected from the group consisting of;

(a) 4-diazo-N-methyl-N-benzylaniline (b) 4-diazo-N-ethyl-N-benzylaniline (c) 4-diazo-N-hydroxyethyl-N-benzylaniline (d) 4-diazo-N-cyclohexyl-N-benzylaniline (e) 4-diazo-N-propyl-N-ethylaniline (f) 4-diazo-N-propyl-N-hydroxyethylaniline g) 4-diazo-Ndipropylaniline (h) 4-diazo-l-morpholinobenzene (i) 4-diazo-2,5-diethoxy-1-morpholinobenzene (j) 4-diazo-N-phenylaniline (k) 4-diazo-N-dimethylam'line (l) 4-diazo-N-diethylaniline (m) 4-diazo-N-ethyl-N-hydroxyethylaniline (n) 4-diazo-3-chloro-N-dimethylaniline; and

(o) 4-diazo-2,5-diethoxy-l-tolylthiobenzene.

6. A diazotype photographic copying material according to claim 1, wherein the amount of said azo dye coupler contained in said light-sensitive layer is in the range of from 1.0 to 10.0 parts by weight per 1.0 part by Weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

7. A diazotype photographic copying material according to claim 4, wherein the amount of said color development accelerator contained in said light-sensitive layer is in the range of from 0.1 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer, the amount of said metal salt contained in said light-sensitive layer is in the range of from 0.1 to 3.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer and the amount of said Xanthine compound contained in said light-sensitive layer is in the range of from 0.5 to 10.0 parts by Weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

8. A diazotype photographic copying material according to claim 2, in which the light-sensitive layer further contains at least one assistant component selected from the group consisting of a color development accelerator, a metal salt and a xanthine compound, said color development accelerator being selected from the group consisting of urea, methylurea, thiourea, benzamide, crotonamide, malonamide, sorbitol, mannitol and pentaerythritol, said metal salt being selected from the group consisting of zinc acetate, aluminum chloride, cadmium sulfate, cadmium nitrate and cadmium chloride and said xanthine compound being selected from the group consisting of caffeine, theophilline and theobromine.

9. A diazotype photographic copying material according to claim 2, wherein said light-sensitive diazonium compound is one member selected from the group consisting of:

(a) 4-diazo-N-methyl-N-benzylaniline (b) 4-diaZo-N-ethyl-N-benzylaniline (c) 4-diazo-N-hydroxyethyl-N-benzylaniline (d) 4-diaZo-N-cyclohexyl-N-benzylaniline (e) 4-diazo-N-propyl-N-ethylaniline (f) 4-diazo-N-propyl-N-hydroxyethylaniline g) 4-diazo-N-dipropylaniline (h) 4-diazo-l-morpholinobenzene (i) 4-diazo-2,5-diethoxy-l-morpholinobenzene (j) 4-diazo-N-phenylaniline (k) 4-diaZo-N-dimethylaniline (l) 4-diazo-N-diethylaniline (m) 4-diazo-N-ethyl-N-hydroxyethylaniline (n) 4-diazo-3-chloro-N-dimethylaniline; and

(o) 4-diazo-2,5-diethoxy-l-tolylthiobenzene.

10. A diazotype photographic copying material according to claim 2, wherein the amount of said azo dye coupler contained in said light-sensitive layer is in the range of from 1.0 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

11. A diazotype photographic copying material according to claim 8. wherein th amount of said color development accelerator contained in said light-sensitive layer is in the range of from 0.1 to 100 parts by weight per 1.0 part by Weight of said light-sensitive diazonium compound contained in said light-sensitive layer, the amount of said metal salt contained in said light-sensitive layer is in the range of from 0.1 to 3.0 parts by weight per 1.0 part by Weight of said light-sensitive diazonium compound contained in said light-sensitive layer and the amount of said Xanthine compound contained in said light-sensitive layer is in the range of from 0.5 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

12. A diazotype photographic copying material according to claim 3, in which the light-sensitive layer further contains at least one assistant component selected from the group consisting of a color development accelerator, a metal salt and a Xanthine compound, said color develop ment accelerator being selected from the group consisting of urea, methylurea, thiourea, benzamide, crotonamide, malonamide, sorbitol, mannitol and pentaerythritol, said metal salt being selected from the group consisting of zinc acetate, aluminum chloride, cadmium sulfate, cadmium nitrate and cadmium chloride and said xanthrine compound being selected from the group consisting of caffeine, theophilline and theobromine.

13. A diazotype photographic copying material according to claim 3, wherein said light-sensitive diazonium compound is one member selected from the group consisting of:

(a) 4-diazo-N-rnethyl-N-benzylaniline (b) 4-diazo-N-ethyl-Nbenzylaniline (c) 4-diazo-N-hydroxyethy1-N-benzylaniline (d) 4-diazo-N-cyclohexyl-N-benzylaniline (e) 4-diazo-N-propyl-N-ethylaniline (f) 4-diazo-N-propyl-N-hydroxyethylaniline (g) 4-diazo-N-dipropylaniline (h) 4-diazo-1-morpholinobenzeue (i) 4-diazo-2,5-diethoxy-l-morpholinobenzene (j) 4-diazo-N-phenylaniline (k) 4-diazo-N-dimethylaniline (l) 4-diazo-N-diethylaniline .(m) 4-diazo-N-ethy1-N-hydroxyethylaniline (n) 4-diazo-3-chloro-N-dimethylaniline; and (o) 4-diazo-2,5-diethoxy-l-tolylthiobenzene.

14. A diazotype photographic copying material according to claim 3, wherein the amount of said azo dye coupler contained in said light-sensitive layer is in the range of from 1.0 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

15. A diazotype photographic copying material according to claim 12, wherein the amount of said color development accelerator contained in said light-sensitive layer is in the range of from 0.1 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer, the amount of said metal salt contained in said light-sensitive layer is in the range of from 0.1 to 3.0 parts by Weight per 1.0 part by Weight of said light-sensitive diazonium compound contained in said light-sensitive layer and the amount of said Xanthine compound contained in said light-sensitive layer is in the range of from 0.5 to 10.0 parts by weight per 1.0 part by weight of said light-sensitive diazonium compound contained in said light-sensitive layer.

References Cited UNITED STATES PATENTS 3,331,689 7/1967 Sosnovsky et al. 96-9l R X 3,169,067 2/1965 Berman et a1 9691 R 2,946,684 7/1960 Sus et a1 96-91 R 3,427,162 2/1969 Halperir 96-91 R 3,565,629 2/1971 'Usbeck 96-91 R 3,224,878 12/1965 Klimkowski et a1. 96-75 X 3,255,007 6/1966 Kosar 96-75 X 3,255,011 6/1966 Welch 96-91 R X 3,331,869 7/1967 Kreuger 96-91 R X 3,353,984 11/1967 Landan 9691 R X 3,386,828 6/1968 Slimowicz 96-91 R X 3,453,112 7/1969 Schaelfer 96-91 R X 3,480,437 11/1969 Slimowicz 96-49 X FOREIGN PATENTS 1,405,542 5/1965 France 96--49 1,078,812 8/1967 Great Britain 96--9l R 983,665 2/1965 Great Britain 96-91 R OTHER REFERENCES Kosar, 1., Light-Sensitive Systems, 1965, pp. 220-230 relied on.

Chem. Abstracts, vol. 75, 37,919]? and 43,145s, Aug. 9, 1971.

Chem. Abstracts, vol. 72, 37,753k, Feb. 23, 1970.

Chemical Abstracts, vol. 74, 4,708n, Jan. 11, 1971.

Chemical Abstracts, vol. 72, 95,3200, May 4, 1970.

CHARLES L. BOWERS, JR., Primary Examiner U.S. Cl. X.R. 96 49; 117-36.8 

